1. Field of the Invention
The present invention relates generally to the field of devices on steering wheels for operating horn switches, and more specifically to an apparatus for extending the surface of horn buttons on a steering wheel, the wheel having a rim connected by spokes to a hub equipped with an inflatable restraint, and the horn buttons being located on the spokes on either side of the restraint, the apparatus including a U-shaped ring member having two ends, placed in an inverted position within the rim, the ends being pivotally attached to the wheel, and the ring member extending upward to rest against the horn buttons and to loop through the space between the restraint and the rim, and which can be quickly located and pressed to rapidly activate the horn.
2. Description of the Prior Art
There have long been buttons and levers on steering wheels for operating horn switches. Many cars made before the mid-nineteen sixties came equipped with a horn activation ring integrally manufactured with the steering wheel. These rings at least partly encircled the hub, dividing the space between the hub and the rim. In an emergency, the driver could simply extend a hand forward within the rim and be reasonably assured of striking the ring and activating the horn. This was an important safety feature because the use of the horn is often most critical in circumstances where there are only seconds to act.
This valuable feature was discontinued on later car models in favor of sleek wheel styling, and replaced with horn buttons on the hub and spokes. Then, inflatable restraint modules were placed on the hub, leaving only the horn buttons on the spokes. In the brief and stressful moments before a collision, the driver may not have time to look down at the wheel to locate these buttons. The time he loses trying to find them by touch can make the difference between successful warning and avoidance, and a fatal accident. The problem, which is most pronounced among the ill, disabled and elderly, has been compounded by the placing of numerous buttons for everything from high beam lights to cruse control on steering wheels. Various horn-activating devices have been developed over the years, but none is both compatable with a hub mounted restraint and able to provide the ready access of the horn ring.
Examples of these prior devices include that of Sladky, U.S. Pat. No. 2,286,016, issued on Jun. 9, 1942. Sladky discloses a steering wheel having a horn switch assembly which includes a pair of resiliently spaced-apart electric contact plates and a horn ring attached to one of the plates, to pivot them together and activate the horn. Although Sladky includes a horn ring as described above, the horn assembly is designed to occupy the entire wheel hub. This prevents the inclusion of a hub-mounted restraint module. Also, Sladky discloses a complete steering wheel which would have to replace an existing wheel, and this would be costly, inconvenient and detrimental to the appearance of the car.
Bonn et al., U.S. Pat. No. 3,712,968, issued on Jan. 23, 1973, teaches a steering wheel having a horn activating baffle plate, fitted with contacts and resiliently spaced above wheel spokes having corresponding contacts. A cup-shaped protrusion on each spoke opposes a cup-shaped recess in the baffle plate and the these opposing cup configurations each contain a spring to achieve the resilient spacing. Bonn et al is intended to eliminate the need for a contact yoke, and thus simplify the horn switch assembly. A problem with Bonn et al is that it cannot be used with an existing steering wheel. The entire wheel must be replaced, at substantial cost and loss of the aesthetic coordination of the original parts. Another problem is that Bonn et al, designed prior to wide commercial production of inflatable restraints, occupies the hub area needed for the restraint module.
Wolf et al, U.S. Pat. No. 3,838,236, issued on Sep. 24, 1974, teaches an elongated switch, suitable for incorporation into a steering wheel to operate a horn. The Wolf et al device covers the hub as well as at least two of the spokes. Wolf et al provides a broad horn activating surface within the wheel rim which is easier to locate than are isolated horn buttons. Localized pressure applied to a restricted area of the switch is sufficient to cause a contact strip to make a connection and blow the horn. A problem with Wolf et al is that, once again, it is not suited for application to an existing steering wheel and is relatively expensive. More importantly, it occupies the space where a restraint module would be located.
Dunford et al, U.S. Pat. No. 3,819,205, issued on Jun. 25, 1974, discloses an inflatable restraint module for mounting on the hub of a steering wheel having four spokes. This design, with its small, isolated horn buttons located on the spokes, presents the very safety problems identified above. Critical time can be lost trying to locate the horn buttons in an emergency.
Fosnaugh et al, U.S. Pat. No. 4,785,144, issued on Nov. 15, 1988, reveals a combination horn-blowing switch and mounting structure for a restraint module. Fosnaugh et al makes the module itself the horn button. A problem with Fosnaugh et al i a it is intended for installation during manufacture of the vehicle. Substantial modification and expense would likely be required to adapt it for use on an existing wheel as an after-market item. Another problem is that many steering wheels today have buttons on and around the restraint module for operating accessories other than the horn. These would be displaced by the Fosnaugh et al device.
Clark et al, U.S. Pat. No. 4,325,568, issued on Apr. 20, 1982, discloses a modular occupant restraint system much like that of Dunford et al, except that it is shown mounted on a two-spoke steering wheel. Husby, U.S. Pat. No. 4,887,843, issued on Dec. 19, 1989, teaches a charging system for a steering wheel-mounted air bag. Clark et al and Husby provide small horn buttons located on the spokes and therefore present essentially the same problems identified above for Dunford et al. So does Brown et al, U.S. Pat. No. 4,504,082, issued on Mar. 12, 1985, which illustrates a small horn button mounted adjacent to the steering wheel rim.
It is thus an object of the present invention to provide an apparatus for operating the horn switch on a modern steering wheel, whether or not the wheel is equipped with a restraint module, which can be quickly and reliably located by touch over a broad area within the rim without looking at the wheel.
It is another object of the present invention to provide such an apparatus which is removable and does not damage or require modification of the wheel.
It is still another object of the present invention to provide such an apparatus which does not detract from the appearance of the car.
It is still another object of the present invention to provide such an apparatus which does not in any way interfere with restraint operation or with handling the steering wheel.
It is finally an object of the present invention to provide such an apparatus which is simple in design, requires no wiring and is inexpensive to manufacture.